Overview
EN ISO 80000-4:2019 - Quantities and units - Part 4: Mechanics is the CEN-adopted edition of ISO 80000-4:2019. The standard defines the names, symbols, definitions and SI units for quantities used in mechanics and, where appropriate, gives conversion factors. It supersedes earlier editions (EN ISO 80000-4:2013 / ISO 80000-4:2006) and is part of the ISO 80000 series on quantities and units. CEN endorsed the text without modification and CEN members were required to implement it as a national standard.
Key topics
The document provides standardized terminology and units for core mechanical quantities, including (examples taken from the standard):
- Mass, mass density, specific volume, relative density
- Linear and surface mass density
- Momentum, impulse, angular momentum
- Force, weight, static/kinetic friction, rolling resistance, drag
- Moment of inertia (tensor), moment of force, torque
- Pressure and gauge pressure
- Stress (tensor), normal and shear stress
- Strain (tensor), relative linear strain, shear strain, volume strain
- Elastic constants: Young’s modulus, shear modulus, bulk modulus, Poisson’s ratio
- Definitions, symbols and SI units (kg, N, Pa, m, s, etc.) and relevant remarks on physical interpretation and conditions
- Where relevant, the standard clarifies conditions (e.g., process assumptions for moduli) and points to related ISO/IEC terminology resources.
Applications and who uses it
EN ISO 80000-4:2019 is aimed at anyone who needs authoritative, consistent mechanical terminology and units:
- Mechanical, civil and aerospace engineers preparing specifications, drawings or calculations
- Metrology and testing laboratories ensuring measurement traceability and reporting
- Technical authors and standards writers creating harmonized documentation
- Software developers and CAE tool vendors implementing unit-aware simulations and data exchange
- Educators and students seeking standardized definitions for teaching mechanics
- Regulatory bodies and procurement teams referencing harmonized units in contracts
Adopting the standard improves clarity, reduces unit-related errors, and ensures consistent data exchange across organizations and international borders.
Related standards and resources
- ISO 80000 series (general on quantities and units)
- ISO Online Browsing Platform and IEC Electropedia for terminological databases and authoritative definitions.
Keywords: EN ISO 80000-4:2019, ISO 80000-4:2019, quantities and units, mechanics, SI units for mechanics, mechanical quantities, units and symbols.